1. Field of the Invention
The invention is related to the field of communication networks, and in particular, to adding wavelengths to optical communication networks using optical regenerator components.
2. Statement of the Problem
Many communication companies use fiber optic cabling as a media for transmitting data because of its high-bandwidth capacity. Fiber optic cables of an optical communication network can reliably transport optical signals over long distances. Over a long distance, the optical signals attenuate in the optical fiber. Consequently, long haul and ultra-long haul optical communication networks need regenerator nodes every 200 km to 500 km to regenerate the optical signals in order to provide a quality optical signal at the receiver end.
Current regenerator nodes regenerate optical signals in the electrical domain. An optical-to-electrical line card in the regenerator node receives optical signals from a fiber span and converts the optical signals into electrical signals. An amplifier amplifies or otherwise regenerates the electrical signals and transmits the regenerated electrical signals to an electrical-to-optical line card. The electrical-to-optical line card converts the regenerated electrical signals into optical signals and transmits the optical signals over a fiber span. The same process takes place in each regenerator node until the optical signals reach the receiver end.
As communication demands rise in the areas served by an optical communication network, the optical communication network may have to be upgraded to increase the capacity. One way to upgrade the capacity of the optical communication network is to add one or more wavelengths to the optical communication network. Traditionally, a wavelength is added to an optical communication network by installing components for the new wavelength that are similar to the components used to implement the current wavelengths. For instance, to add a wavelength to the optical communication network discussed above, network technicians would add an optical-to-electrical line card, an electrical-to-optical line card, and possibly an amplifier to each regenerator node.
One problem with adding new wavelengths in this manner is that it is expensive. Regenerator line cards require high-speed electronics that are difficult and expensive to engineer. Currently, optical-to-electrical line cards and electrical-to-optical line cards each cost about $50,000. If a regenerator node is needed every 200 km to 500 km, the cost of adding a new wavelength to an ultra-long haul optical communication network can quickly rise.